The use of endoscopes for diagnostic and therapeutic indications is rapidly expanding. To improve performance, endoscopes have been optimized to best accomplish their purpose. Therefore, there are upper endoscopes for examination of the esophagus, stomach and duodenum; colonoscopes for examining the colon; angioscopes for examining blood vessels; bronchoscopes for examining the bronchi; laparoscopes for examining the peritoneal cavity, and arthroscopes for examining joint spaces. The discussion which follows will apply to all of these types of endoscopes, whether rigid or flexible.
Instruments to examine the rectum and sigmoid colon, known as flexible sigmoidoscopes, are good examples of the usefulness of endoscopic technology. These devices are expensive and they are used in a contaminated environment for a procedure which is brief (5-10 minutes) and where problems of cleaning time and contamination are important factors. There has been a large increase in the use of the "flexible sigmoidoscope" for use in screening symptomatic and asymptomatic patients to prevent colon and rectal cancer.
Typically, these endoscopes have a flexible insertion tube with multiple small channels that extend along the length of the endoscope and come into contact with body tissues and fluids. These channels allow air insufflation, water flow to wash the tip, and biopsy and suction. Endoscopic accessories that, for example, take a biopsy of tissue samples, are often inserted through at least one of the channels during an endoscopic procedure. As a result, the accessories are grossly contaminated with, for example, blood, stool, mucus, or tissue when removed from the endoscope.
These endoscopic accessories have elongated flexible shafts and a tool, such as forceps, operatively connected to the shaft's distal end. To extend through the endoscope's biopsy channel, the shaft must be longer than the endoscope; for example, in colonoscopy, the colonoscope's shaft is up to two meters long. Although the shaft is preferably resilient, in some cases it must have sufficient stiffness that the rotational and axial positions of the distal end can be controlled by manipulating the proximal end. Furthermore, the accessory must also allow the physician to control the accessory's tool from the shaft's proximal end when the shaft and tool are extended into a patient. As a result of its length and stiffness, the shaft tends to flop around or suddenly move about uncontrollably when the accessory is removed from the endoscope. Unacceptable contamination occurs when the flopping shaft touches equipment, the patient, physicians, or nurses or when a physician or nurse grabs the shaft in an attempt to control the unwieldy instrument.
In addition, an accessory may be contaminated prior to insertion into a patient if the shaft flops around and touches contaminated equipment or is grabbed by a person having contaminants on their gloved hands. Accordingly, an accessory that is difficult to manage or control before, during, and after an endoscopic procedure increases the risk of unacceptable contamination.